1. Field of the Invention
The present invention relates to a method, a system and a terminal apparatus for enabling content purchased by a user to be reproduced in a plurality of terminals by means of a User Identity Module (UIM).
2. Description of the Related Art
With the rapid development of wireless Internet technology and wireless communication technology, a mobile communication terminal user can use various services such as data services and Internet services through both a UIM, which is a module proving the user's own identity, and a terminal. However, such services show a tendency to gradually change into charged services. In order to protect such services, Digital Rights Management (DRM) technology has been gradually introduced.
Such DRM technology corresponds to a representative security technique for protecting content, which stipulates use rights for controlling the use of content. Such DRM technology basically permits encrypted content to be freely distributed among users, but a user's Right Object (RO) is required in order to execute corresponding content. Further, with the increase in the use of a content service due to the development of information communication, unexpected damages have occurred due to the increase in inappropriate copying and distribution. In order to prevent such damages, services of DRM technology based on flexibility and convenience for a user's RO have placed an importance on security in which only permitted users can use a corresponding service. In order to accomplish such security, it is necessary to perform an authentication process for verifying that each user terminal is permitted to have access to a given service.
Generally, mutual authentication is performed only between a terminal and a service provider, and the service provider transfers an RO only to the terminal. Such an RO is designated to be used only by a corresponding terminal. When the RO is to be transferred to or shared by other terminals, the RO can be transferred only to or shared only by specific terminals which have been designated in advance.
FIG. 1 is a block diagram illustrating a general authentication process using a UIM in a Multimedia Broadcast and Multicast Service (MBMS).
Referring to FIG. 1, if authentication is performed between the UIM 30 and a service provider 10, the service provider 10 transfers a Service Key (SK) and a Traffic Key (TK) for decrypting a broadcast service to the UIM 30 through a terminal 20. Then, if the service provider 10 provides the terminal 20 with an encrypted service, the terminal 20 decrypts and executes the encrypted service by means of the keys provided from the UIM 30, so that a user can enjoy multimedia information within the content of the service. The authentication process using the UIM is performed as described above, and the details have been clearly defined in 3GPP TSs 33.220 and 33.102.
As described above, up to the present time, content protection technology has been realized through an authentication process between a service provider and one terminal, etc. However, a detailed method has not yet been proposed for content protection-related standard technology for multiple terminals using a broadcast service in a mobile communication environment. Therefore, a method does not currently exist for reproducing a broadcast service, which a user has joined, in a plurality of terminals by means of a UIM.